1. Psilotum Swartz, J. Bot. (Schrader). 1800(2): 8, 109. 1801.
Whisk-fern [Greek psilos, naked, referring to the plant's leafless aerial shoots]
Plants terrestrial, sometimes epiphytic. Aerial shoots often clumped, simple proximally, dichotomously branched distally, 3(--several)-ridged. Appendages minute, bractlike, borne distally on ridges of aerial shoots, sterile appendages subulate, those subtending synangia 2-lobed. Synangia ± globose, obscurely 3-lobed.
Species 2 or 3 (1 in the flora): tropical and warm temperate regions.
SELECTED REFERENCES
Cooper-Driver,G. 1977. Chemical evidence for separating the Psilotaceae from the Filicales. Science 198: 1260--1262. White, R.A., D.W. Bierhorst, P.G. Gensel, D.R. Kaplan, and W.H. Wagner Jr. 1977. Taxonomic and morphological relationships of the Psilotaceae: A symposium. Brittonia 29: 1--68.
